Day: October 31, 2026

Discovery of Bromochloropyrene Reveals Unexpected Hybrid Properties in Environmental Contaminants

Researchers from Meijo University (led by Professor Takeshi Ohura, with graduate student Natsuki Nasuda) and the National Institute of Animal Health (Dr. Keerthi S. Guruge) have identified bromochloropyrene (BrClPy) as an environmental contaminant in industrial soils and sediments in Japan.

The discovery of bromochloropyrene (BrClPy) has primarily precautionary implications for human health rather than demonstrated acute or widespread risks at current environmental levels.

The aryl hydrocarbon receptor (AhR, also called AHR) is a ligand- activated transcription factor of the basic helix- loop-helix and Per- ARNT-Sim (bHLH- PAS) family.

Infographic illustrating the discovery of Bromochloropyrene, highlighting its properties and significance in environmental contaminants, with locations marked for water and soil sampling sites in Tokyo Bay.
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Researchers from Meijo University (led by Professor Takeshi Ohura, with graduate student Natsuki Nasuda) and the National Institute of Animal Health (Dr. Keerthi S. Guruge) have identified bromochloropyrene (BrClPy) as an environmental contaminant in industrial soils and sediments in Japan.

It is a hetero- halogenated (mixed bromine- and chlorine- containing) polycyclic aromatic hydrocarbon (PAH) with hybrid properties that do not simply match those of purely brominated or chlorinated analogs.

Key findings

  • Occurrence: BrClPy was detected in 10 of 20 surface soil samples from industrial areas along Tokyo Bay (mean concentration 0.13 ng/g) and in 1 of 3 sediment samples from Nagoya Port (mean 0.42 ng/g). Soil concentrations correlated strongly with brominated pyrenes, suggesting formation is more closely tied to bromination processes than to chlorinated pyrenes.⁠
  • Photostability: Under simulated sunlight, BrClPy was roughly half as stable as 1-chloropyrene (similar to the behavior of brominated pyrenes). It primarily lost bromine, forming 1-chloropyrene; loss of chlorine was not observed.⁠
  • Biological activity: In a yeast- based aryl hydrocarbon receptor (AhR) assay, BrClPy showed an estimated potency of 0.18 relative to benzo[a]pyrene. This was similar to dichloropyrene and about 4- 5 times higher than dibromopyrene.

Overall, BrClPy combines the environmental and photolytic behavior of brominated pyrenes with the stronger AhR-mediated activity more typical of chlorinated ones. This points to “emergent” properties of hetero -halogenated PAHs that cannot be predicted from single -halogen compounds alone.

The work (published online September 22, 2026, in Emerging Contaminants, DOI: 10.1016/j.emcon.2026.100758) provides the first evidence of BrClPy contamination in real urban/industrial soils and sediments.

The authors note that monitoring programs may currently overlook mixed-halogen pollutants and call for further research on formation pathways, environmental fate, and biological effects of related compounds to improve risk assessment and regulation.

The study was supported by Japan Society for the Promotion of Science KAKENHI grants.

A hand holding a transparent glass container filled with fine sand, positioned above soil.
Researchers detected bromochloropyrene, a pollutant containing both bromine and chlorine, in soil and sediment samples from industrial areas in Japan, establishing a new class of environmental contaminants with unique biological activities. Credit: tocalcollege from Openverse

The discovery of bromochloropyrene (BrClPy) has primarily precautionary implications for human health rather than demonstrated acute or widespread risks at current environmental levels.

Direct human toxicity data for BrClPy do not yet exist, as it is a newly identified contaminant. Implications are inferred from its aryl hydrocarbon receptor (AhR) activity, its classification as a hetero- halogenated PAH, and the broader toxicology of related halogenated PAHs (HPAHs or XPAHs).

AhR- mediated activity and potential effects

BrClPy activates the AhR with an estimated relative potency of 0.18 compared with benzo[a]pyrene (BaP) in a recombinant yeast assay. This is comparable to dichloropyrene and roughly 4- 5 times higher than dibromopyrene.⁠

AhR is a ligand- activated transcription factor involved in the toxicity of dioxins, certain PCBs, and many PAHs/HPAHs. Chronic activation is associated with:

  • Carcinogenicity (via induction of CYP enzymes, oxidative stress, and related pathways).
  • Endocrine disruption.
  • Immunotoxicity.
  • Developmental and reproductive effects (observed in various model systems for AhR agonists).

BaP itself is an IARC Group 1 human carcinogen, so a compound with measurable relative potency raises concern as a potential contributor to dioxin-like or PAH- like toxicity.

Halogenated PAHs frequently show higher AhR potency than their parent (non-halogenated) counterparts in mammalian and other assays, and they are considered to possess dioxin- like properties.

Exposure context and risk levels

Detected concentrations were low: mean ~0.13 ng/g in industrial soils and ~0.42 ng/g in one harbor sediment sample.

These levels suggest limited direct human exposure via soil contact or dust under typical conditions. Possible routes include:

  • Inhalation of combustion- related particles (HPAHs form during incomplete combustion).
  • Ingestion via contaminated food (bioaccumulation potential in the food chain is a general concern for persistent HPAHs).
  • Dermal contact with soils and sediments in industrial or urban areas.

For the broader class of HPAHs and XPAHs, dietary and indoor air and dust exposure assessments have generally found incremental lifetime cancer risks (ILCR) below or near common thresholds (e.g., 10⁻⁶ to 10⁻⁴) for individual compounds or matrices. However, cumulative risks from multiple PAHs and HPAHs can approach or exceed unacceptable levels in some scenarios.

No quantitative human risk assessment specifically for BrClPy is available yet.

Broader implications

  • Monitoring and regulation gaps: Current environmental monitoring often focuses on parent PAHs or single- halogen compounds and may miss mixed-halogen species like BrClPy. The researchers note that better characterization could improve estimates of human exposure and associated effects, potentially informing future regulations.⁠
  • Additive or synergistic effects: BrClPy’s hybrid photolytic and biological behavior (brominated- like environmental persistence and photolysis combined with stronger chlorinated- like AhR activity) means it may contribute to overall toxic load in ways not fully captured by existing toxic equivalency factors (TEQs) based solely on chlorinated or brominated analogs.
  • Research needs: Further studies are required on bioaccumulation, metabolic activation, chronic toxicity, and actual human biomarkers of exposure. Related work on other HPAHs supports structure–activity relationships linking halogenation pattern and position to AhR potency and downstream effects (e.g., enzyme induction, oxidative stress).

In summary, BrClPy is unlikely to pose significant individual health risks at the trace levels reported, but it adds to the cumulative burden of AhR- active environmental contaminants. Its identification highlights the value of expanding monitoring to hetero- halogenated PAHs for more accurate long-term risk assessment, particularly in industrial and urban settings with combustion sources.

Diagram comparing homo-haloginated PAH and hetero-haloginated PAH, highlighting chlorinated and brominated PAH with an emphasis on photostability and biological properties.
1-s2.0-S240566502600137X-ga1.jpg (308×200)
Hetero-halogenated polycyclic aromatic hydrocarbons as environmental contaminants: Occurrences, photostability, and AhR-mediated activity of bromochloropyrene – ScienceDirect

The aryl hydrocarbon receptor (AhR, also called AHR) is a ligand- activated transcription factor of the basic helix- loop-helix and Per- ARNT-Sim (bHLH- PAS) family.

It functions as an environmental and endogenous sensor. Originally identified as the mediator of toxicity from dioxins (e.g., TCDD), polycyclic aromatic hydrocarbons (PAHs), and related compounds (including halogenated PAHs such as bromochloropyrene), it also responds to dietary, microbial, and metabolic ligands and regulates diverse physiological processes.

Canonical (genomic) pathway

This is the primary and best-characterized mechanism:

  1. Inactive cytoplasmic complex: In the absence of ligand, AhR resides in the cytoplasm as part of a multiprotein complex. This typically includes:
    • Two molecules of heat shock protein 90 (HSP90)
    • Co-chaperone p23 (PTGES3)
    • AhR-interacting protein (AIP/XAP2/ARA9)
    • Often the tyrosine kinase c-Src
      HSP90 stabilizes AhR, prevents degradation, and masks its nuclear localization signal (NLS).⁠
  2. Ligand binding: Agonists (environmental toxins like TCDD, BaP, or BrClPy; endogenous ligands such as FICZ, kynurenine, or microbial metabolites) bind the PAS- B domain. This triggers a conformational change that exposes the NLS and promotes dissociation (or rearrangement) of chaperones.
  3. Nuclear translocation: The ligand- bound AhR moves into the nucleus (sometimes still associated with HSP90 initially).
  4. Heterodimerization: AhR partners with the AhR nuclear translocator (ARNT, also known as HIF- 1β). Structural studies show intimate PAS-B domain interactions between AhR and ARNT in the active complex.⁠
  5. DNA binding and transcription: The AhR– ARNT heterodimer binds xenobiotic and dioxin response elements (XREs and DREs; core motif typically 5′-TNGCGTG- 3′ or similar) in the regulatory regions of target genes. It recruits co- activators and the transcriptional machinery, inducing expression of genes such as:
    • Phase I enzymes: CYP1A1, CYP1A2, CYP1B1
    • Phase II enzymes and other adaptive genes
    • Negative regulators (e.g., AhR repressor/AHRR, TIPARP)
  6. Feedback and termination: Induced CYP enzymes metabolize many ligands (creating a negative feedback loop). AhR itself is subject to ubiquitination and proteasomal degradation. AHRR can compete with AhR for ARNT or DNA binding.⁠

Ligand potency, residence time, and structure influence the strength and duration of the response. Persistent ligands like TCDD produce prolonged activation and more severe toxicity than rapidly metabolized ones like many PAHs.

Non- canonical pathways

AhR signaling is highly context-dependent (cell type, ligand, microenvironment) and extends beyond the classic AhR– ARNT– XRE route:⁠

  • c- Src release and kinase signaling: Ligand binding can free c- Src from the cytoplasmic complex. c- Src then phosphorylates targets such as the epidermal growth factor receptor (EGFR), activating downstream MAPK or other pathways.
  • Crosstalk with other transcription factors: AhR can interact with NF- κB, estrogen receptor (ER), HIF- 1α (competing for ARNT under hypoxia), STATs, or others, leading to trans- repression or alternative gene sets.
  • Non- XRE DNA binding: Partnerships with factors such as KLF6 at non-canonical response elements can drive distinct epigenetic and transcriptional outcomes (e.g., cell- cycle regulation via p21).
  • E3 ubiquitin ligase activity: Ligand- activated AhR can promote ubiquitination and degradation of specific proteins (including itself or other targets).
  • Ligand- independent or stress- induced activation: Mechanical stress, oxidative stress, or other signals can sometimes activate AhR without classical ligands.
  • Cytoplasmic or membrane- proximal effects: Additional non- genomic actions contribute to rapid responses.

Physiological and pathological roles

AhR integrates environmental and endogenous signals. Beyond xenobiotic metabolism and toxicity (carcinogenesis, developmental disruption, immunotoxicity via prolonged activation by pollutants), it regulates:

  • Immune responses (Treg, Th17 balance, barrier integrity, inflammation)
  • Development and tissue homeostasis
  • Host– microbe interactions and diet sensing (tryptophan metabolites)
  • Cancer (context- dependent tumor promotion or suppression)

Therapeutic interest has grown: the AhR agonist tapinarof is approved for psoriasis, and other modulators are in trials for inflammatory diseases, cancer, and infections.⁠

In the context of compounds like bromochloropyrene, AhR activation (measured by reporter assays or CYP induction) serves as a key indicator of potential dioxin- like biological activity and toxicity risk, even though full downstream effects depend on dose, duration, tissue, and co-exposures.

Structural advances continue to clarify ligand recognition (promiscuous but with conserved residues in the PAS- B pocket) and the transition from chaperone- bound to ARNT- bound states, aiding both toxicology and drug design.

Pie charts comparing the composition of surface soil and sediment, highlighting percentages of various compounds including Cl4Py, Br4Py, and others.
Compositions of BrClPy and homo-halogenated Py derivatives in surface soil and sediment samples.
Hetero-halogenated polycyclic aromatic hydrocarbons as environmental contaminants: Occurrences, photostability, and AhR-mediated activity of bromochloropyrene – ScienceDirect

Hetero-halogenated polycyclic aromatic hydrocarbons as environmental contaminants: Occurrences, photostability, and AhR-mediated activity of bromochloropyrene

This is the peer- reviewed paper underlying the Meijo University press release we discussed earlier.

Main findings (from the abstract, press materials, and available excerpts)

Researchers synthesized a reference standard of bromochloropyrene (BrClPy; tentatively a mixture of 1- bromo- 6- chloropyrene and 1- bromo- 8-chloropyrene) for the first time and used it to analyze environmental samples.

  • Occurrence: Detected in 10 of 20 surface soil samples from industrial areas along Tokyo Bay (mean 0.13 ng/g; range <LOD–1.21 ng/g) and in 1 of 3 sediment samples from Nagoya Port (0.42 ng/g mean; one sample 1.27 ng/g). This provides the first evidence of hetero-halogenated (mixed Brand Cl) PAHs in real urban and industrial soils and sediments. Concentrations correlated strongly with brominated pyrenes (1- BrPy and Br₂Py), suggesting formation pathways more similar to bromination processes.
  • Photostability: Under simulated sunlight, BrClPy followed first- order kinetics with a photolysis rate constant of ~0.162 h⁻¹. Photostability was approximately half that of 1- chloropyrene (and similar to 1-bromopyrene and dibromopyrene). The dominant pathway was debromination, producing 1-chloropyrene; dechlorination products were not observed.
  • AhR- mediated activity: In a recombinant yeast assay, BrClPy showed a dose–response relationship (EC₅₀ ≈ 0.43 μM) with a relative potency (REP_BaP) of 0.18 versus benzo[a]pyrene. This was similar to dichloropyrene (REP ≈ 0.20) and 4- 5 times higher than dibromopyrene (REP ≈ 0.04).

Conclusion of the study: BrClPy exhibits hybrid (“emergent”) properties—environmental behavior and photolysis resembling brominated pyrenes, but biological (AhR) activity closer to chlorinated pyrenes. The authors highlight the need for further research on formation, fate, and effects of other hetero-halogenated PAHs to improve monitoring and risk assessment.

Funding came from Japan Society for the Promotion of Science KAKENHI grants 23K21754 and 25K15471.

The full text is behind ScienceDirect’s access controls for many users (institutional or personal subscription and open- access options may apply).

The key results and conclusions are publicly summarized in the EurekAlert release and research- map excerpts.

Title: Hetero-halogenated polycyclic aromatic hydrocarbons as environmental contaminants: Occurrences, photostability, and AhR-mediated activity of bromochloropyrene

Journal: Emerging Contaminants, Volume 12, Issue 4,

Published: December 2026; available online 22 September 2026

DOI: 10.1016/j.emcon.2026.100758

ScienceDirect PII: S240566502600137X

Provided: Meijo University

Authors: Natsuki Nasuda a, Keerthi S. Guruge b, Takeshi Ohura a

aGraduate School of Agriculture, Meijo University, 1-501 Shiogamaguchi, Nagoya, 468-8502, Japan

bDivision of Hygiene Management Research, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, 305-0856, Japan

Abstract

Homo-halogenated polycyclic aromatic hydrocarbons (HPAHs), such as chlorine- or bromine-substituted PAHs, have been ubiquitously distributed in the environment. Conversely, hetero-halogenated PAHs, including chlorine- and bromine-substituted PAHs (halomix PAHs), have not been reported to occur in the environment. This study investigated the environmental occurrence and behavior of bromochloropyrene (BrClPy) as a representative halomix PAH. A BrClPy standard (tentatively a mixture of 1-bromo-6-chloropyrene and 1-bromo-8-chloropyrene) was synthesized for the first time and used for environmental analysis. BrClPy was frequently detected in environmental samples, with mean concentrations of 0.13 ng/g in surface soils from industrial areas and 0.42 ng/g in sediments from industrial harbors. The photostability of BrClPy under simulated sunlight was approximately twofold lower than that of 1-chloropyrene, which was somewhat consistent with the photostability values obtained for 1-bromopyrene and dibromopyrene. The aryl hydrocarbon receptor-mediated activity of BrClPy measured using a recombinant yeast assay showed a potency close to that of dichloropyrene rather than dibromopyrene with an estimated potency of 0.18 relative to benzo[a]pyrene. Consequently, the environmental behavior and biological properties of BrClPy could exhibit the combined characteristics of brominated and chlorinated pyrene.

America closes refineries while the rest of the world races to build them

When Iran closed the Strait of Hormuz at the end of February, the world relearned a lesson it keeps forgetting crude oil, by itself, moves nothing. Trucks, tractors, aircraft and ships run on diesel, gasoline, jet fuel and bunker fuel — transportation fuels that exist only after crude oil has passed through a refinery.

A worker in a plaid shirt holding a blue hard hat stands in front of an industrial site with blurred structures in the background.
Woman construction engineer wear safety white hard hat at construction site industry worker. Female engineer worker civil engineering with hard hat safety helmet. Woman construction Engineer concept

From CFACT

BY RON STEIN AND YOSHIHIRO MURINOKA:

When Iran closed the Strait of Hormuz at the end of February, the world relearned a lesson it keeps forgetting crude oil, by itself, moves nothing. Trucks, tractors, aircraft and ships run on diesel, gasoline, jet fuel and bunker fuel — transportation fuels that exist only after crude oil has passed through a refinery.

Asia felt the shock first. As crude supplies tightened, Asian refiners cut throughput and some curbed transportation fuel exports to protect their own markets. Even after the April ceasefire, tanker traffic through the strait remained far below pre-war levels.

Seven months later, Gulf crude exports are recovering, though many cargoes now travel longer and costlier routes. Diesel is not. In August, Gulf diesel exports were barely a quarter of pre-war levels, as refineries damaged in the war remained offline. In Russia, Ukrainian drone strikes have forced half of the country’s six largest diesel refineries to cut or halt output, and Moscow has banned diesel exports. In February, the Gulf and Russia together supplied nearly half of the world’s seaborne diesel. A damaged diesel unit cannot be replaced quickly, and the diesel capacity lost to war and refinery closures may take years to replace.

The ripple reached California. The state has spent years making refining harder. Two refineries have recently closed, and more of the remaining seven are expected to follow. The gap is filled by imports, much of it from Asia. California’s policies did not reduce the state’s demand for refined products. They simply moved the source of those products across the Pacific — and into the path of a crisis on the other side of the world.

The step that makes raw crude oil resources usable

Modern life demands thousands of products, from medicines and fertilizers to plastics, lubricants, and transportation fuels. Most begin as crude oil, natural gas, or coal, which must be refined, gasified, or cracked before they can serve as feedstocks for manufacturing. Crude oil alone yields more than 6,000 products.

Natural resources have latent value. Processing is what makes that value usable. A nation that controls this step controls much of its economic future.

The developing world wants its own refineries

It is no surprise, then, that nations across Asia, Africa, and the Middle East want refineries of their own. Rising incomes mean rising transportation fuel demand, and the Hormuz crisis has shown every importer the cost of depending on someone else’s refinery.

Industry databases list roughly 180 new refinery projects announced or planned worldwide for this decade, about 70 of them in Africa. OPEC expects some 5.8 million barrels per day of new refining capacity by 2030, more than 90 percent of it in Asia-Pacific, Africa and the Middle East.

Announced is not built

Engineers know that a project announcement is only the beginning. A refinery must pass through planning, environmental assessment, permitting, financing, front-end engineering, construction, and commissioning. Each stage is a filter.

One of us studied China’s coal-to-gas sector during its boom a decade ago, when dozens of synthetic natural gas projects were announced. Years later, only four were in operation.

Refining is proven technology, so attrition will be far lower. But the lesson holds: count what is being built, not what is being announced. Even so, roughly half of expected capacity growth is already operating or under construction — several million barrels per day. The demand for refined crude oil is real and growing worldwide.

Who can build refineries?

The bottleneck is not ambition. It is capability.

The core process technologies — hydrocracking, catalytic cracking, reforming—are licensed by only a handful of companies. Perhaps two or three dozen engineering, procurement, and construction (EPC) contractors worldwide can deliver a large grassroots refinery. Heavy-wall reactors and large compressors come from a limited number of manufacturers, with long delivery times. The same contractors, compressor makers, and commissioning teams are now needed to repair war-damaged refineries in the Gulf — competing directly with new projects in the developing world. And a refinery needs trained operators, maintenance crews and a regulatory system capable of overseeing it safely. The refinery technical talent cannot be imported overnight.

A refinery can be closed in months. Building one takes five to seven years or more.

Who will pay?

A large refinery costs billions of dollars. Nigeria’s 650,000-barrel-per-day Dangote refinery cost roughly $20 billion.

At the very moment developing nations need this capital, multilateral lenders and many Western banks have stepped back from fossil fuel projects in the name of climate policy. Chinese contractors, meanwhile, arrive with state-backed financing and a construction team in a single package.

Whatever one thinks of the “debt trap” debate, the structure is clear: those who finance and build a nation’s refineries gain lasting influence over its transportation fuel supply. Western climate finance policies have not reduced developing nations’ need for refined products. They have only changed who builds the refineries.

Pollution moves; it does not disappear

Imported fuels must meet U.S. product specifications, and ships are subject to international limits on fuel sulfur, with stricter rules near North American coasts. But the emissions and safety standards at the refinery itself are set where the refinery stands — often far looser than in California.

Closing a tightly regulated California refinery and importing from one with weaker standards, then shipping the product thousands of miles, does not clean the air. It exports the emissions and adds the voyage.

A view from Asia

For Asia, conflict in the Gulf is not a distant event. It is paid for at the pump in Tokyo, Seoul, Mumbai, and Manila, and in the price of every product that depends on refined crude oil. When the strait closes, Asian refineries run short, and the shortage travels on to California.

What the world needs is not another round of escalation but the restoration of free and stable navigation. America should remember that some 95 percent of the world’s 8 billion people live outside its borders. It can end the policies that are forcing its own refineries to close, and help developing nations build theirs well — with technology, training, and financing.

Japan knows this work. For decades, Japanese engineering firms have built refineries, petrochemical complexes, and gas plants across the Middle East and trained the people who run them.

Crude oil is not useless; it is unfinished. Refining completes it. The nations that understand this are building refineries. The question is whether America, Japan, and other partners will help them do it — or leave the job, and the influence, to others.

This article originally appeared at America Out Loud

NASA’s Decade of Space-Based CO₂ Data Gets a Major Upgrade—Sharpening the View of Earth’s Carbon Cycle

An improved multi- year record of atmospheric CO₂ from NASA’s Orbiting Carbon Observatory instruments (OCO- 2 and OCO- 3), based on updated data-processing algorithms.

It primarily improves observational constraints and validation for carbon- cycle and atmospheric inversion models, which in turn support and refine the carbon- cycle components of broader climate- Earth- system models.

It affects climate projections mainly indirectly, by improving constraints on the carbon cycle, the processes that determine how much of emitted CO₂ stays in the atmosphere versus being absorbed by land and oceans.

Infographic of NASA's Orbiting Carbon Observatory (OCO-2 and OCO-3) tracking global carbon dioxide levels, featuring Earth with CO2 concentration data, orbital tracks, and satellite specifications.
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An improved multi- year record of atmospheric CO₂ from NASA’s Orbiting Carbon Observatory instruments (OCO- 2 and OCO- 3), based on updated data-processing algorithms.

The Eos Research Spotlight (published 30 October 2026 by science writer Sarah Stanley) summarizes a paper by Taylor et al. in Earth and Space Science. Every day, OCO- 2 and OCO- 3 collect more than a million observations of sunlight reflecting off Earth’s surface.

An algorithm converts these into estimates of atmospheric carbon dioxide concentrations (specifically, the column- averaged dry- air mole fraction, XCO₂).

OCO-2 has operated as a free- flying satellite since its 2014 launch; OCO- 3 was installed on the International Space Station in 2019. Together they have provided extensive global coverage and supported studies of the carbon cycle’s responses to events such as wildfires, droughts, and El Niño.

Researchers applied version 11 (v11) of the Atmospheric Carbon Observations from Space (ACOS) Level 2 full- physics retrieval algorithm.

Improvements include:

  • Better instrument calibration
  • Updated handling of factors such as clouds, aerosols, and how sunlight reflects off the ocean
  • Refined quality filtering and bias correction

The resulting record runs from September 2014 through (at least) August 2026-more than a decade. Compared with earlier algorithm versions, the new data generally agree more closely with highly accurate ground-based measurements from the Total Carbon Column Observing Network (TCCON).

OCO- 2 and OCO- 3 also show close agreement with each other (mean difference <0.2 ppm in collocated observations), despite different viewing angles, times, and orbital paths.

The upgraded dataset supports month- by- month (rather than only year- by-year) tracking of atmospheric CO₂ buildup. This enables nearer- real- time monitoring of how extreme events affect the carbon cycle.

The publicly available record is positioned as a benchmark for advancing understanding of the global carbon cycle and for assessing the effectiveness of climate policies.

Thomas E. Taylor et al., “The OCO-2 and OCO-3 ACOS Version 11 XCO₂ Data Products: A Benchmark Record for Space- Based Global Carbon Cycle Research,” Earth and Space Science (2026), https://doi.org/10.1029/2026EA005360.[](https://phys.org/news/2026-10-decade-carbon-dioxide-space.html)

The Eos article itself is available at: https://eos.org/research-spotlights/a-decade-of-carbon-dioxide-data-from-space-gets-an-upgrade.

View of Earth from space with a reddish haze, indicating atmospheric distortion or pollution.
This image is a visual representation of atmospheric carbon dioxide levels as modeled by NASA’s Goddard Earth Observing System, which incorporates data from the Orbiting Carbon Observatory-2 satellite. Credit: Scientific Visualization Studio, NASA

It primarily improves observational constraints and validation for carbon- cycle and atmospheric inversion models, which in turn support and refine the carbon- cycle components of broader climate- Earth- system models.

NASA’s OCO- 2 (since 2014) and OCO- 3 (since 2019) measure the column-averaged dry- air mole fraction of CO₂ (XCO₂). The v11 algorithm updates (better calibration, handling of clouds- aerosols- and ocean- reflectance, quality filtering, and bias correction) produce a more consistent record from September 2014 onward that agrees more closely with ground- based TCCON measurements and shows reduced variance and less temporal divergence relative to atmospheric inversion models used as “truth proxies”. OCO- 2 and OCO- 3 also agree with each other to within a mean difference of <0.2 ppm.

These improvements affect modeling in several concrete ways:

  • Stronger constraints on surface flux inversions
    Atmospheric inversion models (top- down approaches) assimilate XCO₂ data (alongside in- situ measurements) to estimate net CO₂ fluxes between the surface and atmosphere, i.e., the balance of anthropogenic emissions, land sinks, and ocean uptake. The cleaner, more consistent v11 data reduce systematic errors and provide better- characterized uncertainties. This leads to higher-fidelity estimates of regional- to- global fluxes, seasonal- to-interannual variability, and responses to events such as wildfires, droughts, and El Niño. An OCO- 2 v11 Model Intercomparison Project (MIP) is already underway to quantify the impact of the version change on flux estimates.
  • Better evaluation and diagnosis of carbon- cycle processes in Earth- system models
    Climate and Earth- system models include interactive land and ocean carbon components that simulate photosynthesis, respiration, fires, ocean uptake, etc. The multi- year satellite record serves as an independent check on simulated atmospheric CO₂ growth rates, seasonal amplitudes, and spatial patterns. Prior OCO data have already highlighted discrepancies (e.g., many dynamic vegetation models underestimating the seasonal amplitude of the terrestrial carbon cycle). The upgraded record, with lower errors and month- by- month tracking capability, allows finer diagnosis of model strengths/weaknesses, especially for extreme- event responses and carbon- climate feedback.⁠
  • Support for higher- resolution and near- real- time applications
    The ability to monitor atmospheric CO₂ accumulation on monthly rather than only annual timescales helps evaluate how models represent short-term variability and extreme events. Combined OCO- 2 and OCO- 3 sampling also improves coverage in some regions (though OCO- 3’s orbit introduces its own sampling challenges that inversions must handle).
  • Indirect benefits for climate projections and policy assessment
    More accurate flux estimates and carbon- cycle understanding feed into assessments of the remaining carbon budget, the strength of natural sinks, and the effectiveness of mitigation policies. These, in turn, inform the scenarios and feedback parameterizations used in climate projections. The paper positions the v11 record as a “benchmark” for space- based global carbon-cycle research precisely because of these uses.

The data improve constraints and validation, not the underlying model physics directly. Differences between v10 and v11 XCO₂ will propagate into revised flux estimates, so earlier inversion results may need updating. OCO-3’s irregular sampling and limited high-latitude coverage still require careful treatment in inversions. Overall agreement with models and TCCON is improved but not perfect; residual biases remain at the level of tenths of a ppm in some cases.

In short, the upgrade delivers a more reliable observational backbone for carbon -cycle science. This tightens the link between satellite measurements, flux estimates, process understanding, and the carbon- cycle modules embedded in climate models, ultimately supporting more robust assessments of how the Earth system is responding to rising CO₂.

Global map showing locations of OCO-3 SAMs/Targets acquired from July 2019 to December 2025, with a bar chart indicating the number of acquisitions by category.
The OCO‐2 and OCO‐3 ACOS Version 11 XCO<sub>2</sub> Data Products: A Benchmark Record for Space‐Based Global Carbon Cycle Research – Taylor – 2026 – Earth and Space Science – Wiley Online Library

It affects climate projections mainly indirectly, by improving constraints on the carbon cycle, the processes that determine how much of emitted CO₂ stays in the atmosphere versus being absorbed by land and oceans.

This reduces uncertainty in carbon- climate feedback, which are a significant source of spread in future warming estimates for any given emissions pathway.

Climate projections (e.g., those from CMIP Earth – system models used in IPCC assessments) depend on:

  • Emissions scenarios (SSPs or similar).
  • Climate sensitivity.
  • Carbon- cycle feedback: how warming, droughts, fires, and other changes alter natural sinks, potentially leaving more CO₂ in the air and amplifying warming.

The upgraded OCO- 2 and OCO- 3 ACOS v11 XCO₂ record (2014– present, with better calibration, lower systematic errors, closer agreement with ground measurements, and consistency between the two instruments) strengthens the observational foundation for the carbon- cycle side in these ways:

  • Better flux estimates via atmospheric inversions
    The cleaner, longer, and more consistent satellite data are assimilated into inversion models to estimate surface CO₂ fluxes (net land and ocean sinks). Reduced variance relative to prior versions and truth proxies (including inversion models themselves) and the ongoing OCO-2 v11 Model Intercomparison Project should yield more reliable regional- to- global flux estimates and better characterization of interannual variability. These observationally constrained fluxes serve as benchmarks for the carbon- cycle modules in Earth-system models.⁠
  • Improved evaluation of carbon- cycle processes and feedback
    Prior OCO data already showed that many dynamic vegetation models underestimate the seasonal amplitude of the terrestrial carbon cycle compared with satellite- and in- situ- constrained fluxes; models with larger (more realistic) amplitudes also tend to show greater sensitivity to climate change over the historical period. A higher- quality multi- year record allows tighter evaluation of how models represent responses to extremes (El Niño, droughts, wildfires). Recent analyses using OCO- related data have highlighted unusually weak land sinks in some years, testing whether models adequately include rapid carbon-loss processes (e.g., extreme fires, climate- driven mortality). Deficiencies here can make some projections of remaining carbon budgets overly optimistic.⁠
  • Month- by- month monitoring capability
    The improved record supports tracking atmospheric CO₂ accumulation on monthly rather than only annual timescales. This enables nearer- real- time detection of carbon- cycle anomalies linked to extreme events, providing an early-warning capability that can inform updates to near- term projections, carbon budgets, and model benchmarking for decadal predictions.⁠
  • Support for remaining carbon budgets and policy assessment
    More accurate knowledge of current sink strengths and their variability helps refine estimates of how much CO₂ can still be emitted while staying below temperature targets (the remaining carbon budget). It also aids evaluation of whether observed atmospheric growth rates are consistent with reported emissions and policy actions, feeding into updated scenario assessments.

The upgrade does not directly alter emissions scenarios, equilibrium climate sensitivity, or the physical climate components of models. Quantitative impacts on specific projected temperature ranges or carbon budgets from the v11 dataset itself are not yet available (the paper is very recent). Effects will appear gradually as the data are incorporated into inversions, model evaluations, and subsequent assessment cycles.

In summary, the upgraded satellite record provides a stronger observational benchmark for the carbon cycle. This helps reduce (or at least better quantify) a key uncertainty in climate projections, the strength of carbon- climate feedback, and supports more reliable estimates of remaining carbon budgets and the effectiveness of mitigation efforts.

Scatter plot comparing GEOS5 FP-IT prior wind speeds against AMSR2 medium frequency wind speeds.
The OCO‐2 and OCO‐3 ACOS Version 11 XCO<sub>2</sub> Data Products: A Benchmark Record for Space‐Based Global Carbon Cycle Research – Taylor – 2026 – Earth and Space Science – Wiley Online Library

The OCO-2 and OCO-3 ACOS Version 11 XCO2 Data Products: A Benchmark Record for Space-Based Global Carbon Cycle Research

This is the primary research paper behind the Eos spotlight.

NASA’s Orbiting Carbon Observatory- 2 (OCO-2, since September 2014) and OCO-3 (on the ISS since August 2019) measure the column- averaged dry- air mole fraction of CO₂ (XCO₂) from reflected near- infrared sunlight. This paper describes the version 11 (v11) Atmospheric Carbon Observations from Space (ACOS) Level 2 full- physics retrieval algorithm, including updates to quality filtering and bias correction.

Key improvements and results:

  • Updates include better instrument calibration, spectroscopy (ABSCO tables), meteorology and prior profiles, ocean surface reflectance parameterization, digital elevation model, and handling of clouds and aerosols.
  • The resulting XCO₂ products show reduced systematic errors and better agreement between actual and theoretical uncertainties (especially for OCO- 3) compared with the previous v10 versions.
  • Validation against the Total Carbon Column Observing Network (TCCON) and atmospheric inversion models (used as truth proxies) shows reduced variance and less temporal divergence.
  • Collocated OCO- 2 and OCO- 3 observations agree to a mean difference of <0.2 ppm across their overlapping period, better than either dataset agrees with the validation sources.
  • The unified, inter- calibrated record spans September 2014– August 2026 (OCO-2) and August 2019 onward (OCO- 3). Data are publicly available from the NASA Earthdata Cloud (including both X2007 and X2019 WMO scales, plus low-latency forward-stream files).

Conclusions from the paper

The lower and better- characterized errors “should enable higher- fidelity carbon cycle science studies, at local, regional, and global scales.” Together with related GOSAT v11 data, these products form a long- term global benchmark record for space- based carbon- cycle research.

The paper itself focuses on the retrieval algorithm, data quality, and validation rather than directly quantifying impacts on climate models or projections. Those applications (flux inversions, carbon- cycle evaluation, remaining carbon budgets, etc.) are enabled by the improved dataset, as discussed in our earlier exchanges.

Full text is available via the Wiley link (institutional access or purchase may be required) or through repositories such as CaltechAUTHORS. Data products can be downloaded from NASA Earthdata.

NASA Earthdata is the primary public portal for accessing the upgraded OCO- 2 and OCO- 3 data products discussed in the Taylor et al. (2026) paper.

Main access point

All Level 2 Lite File (LtCO2) products, forward- stream files, and related documentation for the ACOS Version 11 XCO₂ data are freely available through the NASA Earthdata Cloud / GES DISC.

Key datasets from the paper

InstrumentVersionProductDOI / Notes
OCO- 2v11.2OCO2_L2_Lite_FP_11.2rhttps://doi.org/10.5067/70K2B2W8MNGY
OCO- 2v11.3OCO2_L2_Lite_FP (recommended after 1 Jan 2024)Current production version (includes icing correction)
OCO- 3v11OCO3_L2_Lite_FP_11rhttps://doi.org/10.5067/8U0VGVQC7HZG
  • Data are provided on both the older X2007 and current X2019 WMO CO₂ scales.
  • Low- latency (forward- stream) daily files are also available (typically within ~2 days of observation).
  • Supporting files include L1b, meteorology, preprocessor, and diagnostic products.

How to get the data

  1. Go to earthdata.nasa.gov and create a free Earthdata Login account (required for downloads).
  2. Use Earthdata Search and search for “OCO- 2” or “OCO- 3” and “Lite FP” or the specific version (e.g., “OCO2_L2_Lite_FP_11”).
  3. Or go directly via the GES DISC portal linked from Earthdata.

Useful documentation

  • Data User’s Guide for OCO- 2 (v11.3) and OCO- 3 (v11)
  • Data Release Statements for each version
  • Available on the GES DISC documentation pages or via the links in the Taylor et al. paper.

Journal: Earth and Space Science, Open Access, Volume13, Issue10

DOI: 10.1029/2026ea005360

First published: 22 October 2026

Provided: Eos

Authors: Thomas E. Taylor, Christopher W. O’Dell, Albert Chang, Abhishek Chatterjee, Cecilia Cheng, Lan Dang, Saswati Das, Brendan Fisher, Dejian Fu, Jonathan Hobbs, Nicole Jacobs …

Abstract

NASA’s Orbiting Carbon Observatory-2 (OCO-2) and OCO-3 have been observing Earth’s atmosphere from space since September 2014 and August 2019, respectively. The version 11 (v11) Atmospheric Carbon Observations from Space (ACOS) Level 2 full physics (L2FP) retrieval algorithm has been used to provide estimates of the column-averaged dry-air mole fraction of carbon dioxide (XCO2) from OCO measurements of surface reflected near-infrared solar radiation. In this work, updates to the ACOS v11 retrieval algorithm are discussed, and the quality filtering and bias correction of the XCO2 products are described. XCO2 estimates from OCO-2 and OCO-3 are compared to Total Carbon Column Observing Network (TCCON) observations and to atmospheric inversion models, which serve as truth-proxies for XCO2. In addition, a direct comparison of collocated soundings between OCO-2 and OCO-3 is performed. Variations in v11 XCO2 over small areas show improvement in agreement between actual and theoretical uncertainties, suggesting a reduction in systematic errors compared to v10, especially for OCO-3. There is reduced variance in the new v11 XCO2 product relative to truth-proxies, including less divergence in the XCO2 values with time against models. The collocations of XCO2 observations between OCO-2 and OCO-3 indicate an overall mean difference of <0.2 ppm across the overlapping time range. Furthermore, OCO-2 and OCO-3 agree better with each other than they do with the validation sources, suggesting a well conditioned and unified set of XCO2 concentrations that can be used concurrently for carbon cycle studies to provide a benchmark record spanning September 2014 through August 2026.

Energy Crisis Deepens: Natural Gas 10x U.S. Prices Threaten Industry Collapse as Sinn Calls Energiewende “All Humbug”

European (especially German and EU) wholesale natural gas prices have recently been trading at roughly 10- 12 times U.S. levels, creating severe competitive pressure on energy- intensive basic industries.

Hans- Werner Sinn, the former long- time president of the ifo Institute, delivered a sharp critique of Germany’s Energiewende (energy transition) in a lecture on 9 October 2026 at the University of Lucerne (hosted by the Institut für Schweizer Wirtschaftspolitik- IWP).

A somber scene depicting an industrial landscape with factories and smoke stacks, highlighting an energy crisis with text indicating natural gas prices are ten times higher in the U.S. A concerned figure gestures towards declining industry output, while graphs show rising trends and falling production.
AI generated by Grok

European (especially German and EU) wholesale natural gas prices have recently been trading at roughly 10- 12 times U.S. levels, creating severe competitive pressure on energy- intensive basic industries.

As of late October 2026, the Dutch TTF benchmark (Europe’s main wholesale gas price reference) has climbed above €97– €100 and more /MWh (and higher intraday), its highest levels since late 2022.

This follows a sharp rise from earlier 2026 levels around €30- €35/MWh, driven by winter demand concerns, storage dynamics, Middle East tensions affecting energy markets, and Europe’s structural reliance on higher- cost LNG after the loss of most Russian pipeline supply.⁠

In contrast, the U.S. Henry Hub benchmark has been around $2.80–$3.00/MMBtu (roughly equivalent to €7–8/MWh after unit conversion). Converted to comparable energy units, this produces a European premium of about 10–12× (sometimes cited near 11- 13× on peak days).

Why the gap exists and persists

Natural gas markets are regional rather than fully global. U.S. shale production keeps domestic prices low and abundant. Shipping gas to Europe requires liquefaction, tanker transport, and regasification, adding substantial cost, so Europe’s marginal supply is often LNG priced well above Henry Hub.

Pre- 2022, Europe benefited from cheaper Russian pipeline gas; the shift to LNG (and earlier policy choices on domestic production/nuclear) has left a structural premium. Even in quieter periods the ratio has often stayed in the 3–5 times range; recent spikes have pushed it much higher.⁠

German official data (Destatis) reflect rising industrial energy costs: producer prices for energy rose sharply year- on- year in recent months (e.g., energy component +14.9% in one September report), with natural gas distribution prices elevated. This feeds into higher costs for manufacturing.

Impact on basic industry

Energy- intensive sectors, chemicals, fertilizers (ammonia), steel, glass, ceramics, paper, use natural gas both as fuel and feedstock. A 10 times price differential makes European production structurally uncompetitive against U.S. (or other low- cost) rivals.

Consequences already observed or warned about include:

  • Reduced capacity utilization (e.g., German chemical plants operating well below historical norms).
  • Temporary shutdowns, permanent closures, or relocation of production/investment.
  • Erosion of export margins and acceleration of deindustrialization risks in Germany and wider Europe.
  • Higher electricity prices (gas often sets the marginal price), compounding the problem.⁠

Industry voices and analyses (including earlier Draghi competitiveness reports noting 4- 5 times gaps) have long flagged this as a core competitiveness handicap. Current spikes intensify warnings that basic industry faces decline without relief on energy costs, storage security, or alternative supplies.

In short, the headline accurately captures a real and acute market reality as of late October 2026: Europe’s gas costs remain dramatically higher than the U.S., threatening the viability of energy- intensive manufacturing.

Hans- Werner Sinn, the former long- time president of the ifo Institute, delivered a sharp critique of Germany’s Energiewende (energy transition) in a lecture on 9 October 2026 at the University of Lucerne (hosted by the Institut für Schweizer Wirtschaftspolitik- IWP).

Key points from Sinn’s assessment

  • Broken promises: Politicians had claimed the transition would deliver cheap energy, open new export markets for German technology, and establish Germany as a global climate leader. Sinn argues none of these materialized. Instead, electricity costs remain high, industry is under severe pressure, and Germany has not become a model others follow.
  • Technical and economic flaws: Wind and solar are weather- dependent. This requires near-full back up from conventional (often fossil) plants, storage, and expanded grids, creating a costly dual system with high fixed costs. He estimated renewables (especially wind and solar) still account for only a modest share of total final energy consumption (around 9 percentage points from wind and solar in some of his figures, with overall renewables higher but far short of full replacement). Achieving climate neutrality by 2045 would require roughly a tenfold expansion of wind and solar within about two decades, something he views as unrealistic given storage, grid, permitting, and acceptance constraints.⁠
  • Climate targets: Germany’s statutory goals (65% emissions cut by 2030 vs. 1990, 88% by 2040, net- zero by 2045) are, in his view, out of reach under current technology and economics. Past emissions reductions partly reflect industrial decline rather than pure efficiency or clean- energy success.
  • Carbon leakage and unilateral action: Unilateral European cuts in fossil demand simply shift production (and emissions) elsewhere while potentially lowering global fossil prices, encouraging more consumption abroad. He applies similar logic to the combustion- engine phase- out and oil- heating bans: reduced German demand does not eliminate the fuel; it is burned elsewhere, sometimes with higher overall emissions.
  • Broader context: Sinn frames the Energiewende as part of a deeper structural crisis, the most severe since World War II, driven by high energy costs (linked to the nuclear phase, out and loss of cheap Russian gas), bureaucracy, ESG rules, and social policy. He has called for “unwinding 15 years of Merkel policies”, a return to nuclear power, accelerated depreciation to spur investment, longer working lives, workfare over welfare, and a more realistic international climate approach rather than European go-it-alone targets.

Sinn does not deny human- caused climate change. His long- standing critique focuses on the design and feasibility of Germany’s specific policy path: intermittency costs, missing storage at scale, carbon leakage, and the damage to industrial competitiveness. The IWP lecture and subsequent coverage (including podcasts and articles) present this as a comprehensive settling of accounts with the transition’s results versus its original sales pitch.